The present invention relates in general to devices which are adapted to retain bearing cups onto the ends of universal joint trunnions. In particular, the present invention relates to an improved device for quickly and reliably retaining such bearing cups on a universal joint cross during purging and shipment thereof.
Universal joints are well known devices which provide a driving connection between two members adapted to rotate about respective non-aligned axes of rotation. Universal joints of this type are widely used between rotatable drive shafts in vehicles. Typically, such universal joints include a cross formed by a central body portion having four trunnions extending outwardly therefrom. The trunnions are disposed in a single plane at right angles relative to one another. A bearing cup is rotatably mounted over the end of each of the trunnions. Each of the two opposed pairs of bearing cups is secured to a yoke. The yokes are respectively secured to the rotatable members to provide the universal joint connection therebetween.
When installing universal joints of this type, the following assembly process is frequently followed. A first yoke is initially secured to its associated first rotatable member at a first assembly location, while the bearing cups are mounted on the universal joint cross. One of the two opposed pairs of bearing cups on the cross is then secured to the first yoke. At this point, therefore, only the secured one of the two pairs of the bearing cups is positively retained in position relative to the cross. The other opposed pair of bearing cups remains mounted on the cross, but is not positively retained thereon. Next, the cross is purged with lubricant. Such purging is well known in the art and involves the injection of lubricant within the cross at a relatively high pressure. Subsequent to such purging, the first rotatable member (having the purged cross secured to the first yoke) is shipped to a second assembly location, where the other opposed pair of the bearing cups is secured to a second yoke and its associated second rotatable member.
Several drawbacks have been identified with the above described assembly process. First, as mentioned above, one of the opposed pairs of bearing cups (the pair which is not secured to the first yoke) is not positively retained in position on the cross when the cross is purged with lubricant. As a result, these non-retained bearing cups tend to move apart from one another on the cross during the purging process because of the relatively high pressure created therein. Often, the bearing cups move apart to relative positions which prevent them from being easily assembled into the second yoke. It is known to clamp these bearing cups together during the purging process to reduce this problem. Unfortunately, residual pressure within the cross after completion of the purging process has been known to cause such movement after the clamps are removed.
A second problem identified with the above described assembly process is that the non-retained bearing cups occasionally fall off the cross and become lost during shipment. This generally occurs as a result of an impact to the cross, which is usually exposed during shipment. Also, the high lubricant pressure within the cross may cause the bearing cups to move apart from one another so far that they fall off of the trunnions. Straps are known for retaining the bearing cups on the cross, but it is time-consuming to install such straps for shipment and remove them for subsequent assembly of the universal joint. Thus, it would be desirable to provide a device for quickly and easily retaining the non-retained bearing cups in position on the cross during purging and shipment thereof, and which may be left on the cross during subsequent assembly.